RYS - EC01 Load Combination

EC LOAD COMBINATIONS

from Eqs. 6.10, 6.10a or 6.10b of EN1990

Σγ_G,j∙G_k,j + γ_Q,1∙Q_k,1 + Σγ_Q,i∙ψ_0,i∙Q_k,i
G_k,j        Permanent actions e.g., weight of steel and concrete; soil
Q_k,1        Leading variable action
Q_k,i        Accompanying variable actions
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ψ : combinations factors
Details for γ and ψ in EN 1990: 2002. (see below)

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Actions
Partial factors for actions γ :
Unfavourable conditions:
Permanent action (G) / Dead load (DL) :        1.35
Variable action (Q) / Imposed load (IL) :        1.5

Favourable conditions:
Permanent action (G) / Dead load (DL) :        1.0
Variable action (Q) / Imposed load (IL) :        0

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Accident Limit State
E_d = γ_G∙G_k + γ∙A_d + ψ₁∙Q_k,1 + ψ₂∙Q_k,2
A_d = accidental action
Q_k,1 = leading variable action (e.g., imposed load)
Q_k,2 = accompany variable load (e.g., temperature load)
γ = 1.0 for accidental event
ψ_i = reduction factors for accompany variables, see (Table NA.A1.1 in EC0)

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Values of ψ_0,i are found in *NA to SS EN 1990: 2008+A1: 2010):
Action        ψ₀
Imposed loads
Category A: domestic, residential areas :        0.7
Category B: office areas :        0.7
Category C: congregation areas :        0.7
Category D: shopping areas :        0.7
Category E: storage areas :        1.0
Category H: roofs :        0.7
*For MRT use Category C: congregation areas , ψ₀ = 0.7
Wind loads on buildings :        0.5
Temperature :        0.6

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Example of Accident Limit State Load Combinations

E_d = γ_G∙G_k + γ∙A_d + ψ₁∙Q_k,1 + ψ₂∙Q_k,2
(near MRT Station : use Congregation area for ψ₁ and ψ₂ )

Leading variable : Imposed load (IL)
E_d = Self Weight + Strut Force + 1.0∙A_d + 0.7∙IL + 0∙Temperature

Leading variable : Temperature load (IL)
E_d = Self Weight + Strut Force + 1.0∙A_d + 0.5∙Temperature + 0.6∙IL

Note:
Gk = Self Weight + Strut Force
A_d = accidental load (such as impact or one strut removal)
Q_k,1= leading variable action (e.g., imposed load)
Q_k,2= accompany variable (e.g., temperature load)

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